Recently, a technology for realizing an interactive dialogue between a human and a machine has become widespread. For having a dialogue between a human and a machine with communication, artificial intelligence (AI) and voice recognition technologies are required, but with a context analysis and a response alone, communication cannot be established. A technology for estimating a human's emotion and the like is required.
For example, Patent Literature 1, Unexamined Japanese Patent Application Kokai Publication No. 2006-178063 discloses a technology for estimating emotion of a user who is a dialogue partner and utilizing the estimated emotion for a dialogue. In Patent Literature 1, utterance contents are converted to text every time a user makes an utterance and the user's emotion is estimated by whether a word showing good or bad emotion is included in the text. A device replies depending on the estimated emotion (for example, if the estimated emotion is negative, the device utters “Are you OK?” or the like).
Patent Literature 2, Unexamined Japanese Patent Application Kokai Publication No. 2014-219594 discloses a technology of recognizing emotion of a user from user's voice and selecting a conversation algorithm that corresponds to the emotion of the user.